In a vehicle such as an automobile, in a condition that a seat back of a seat is reclined or stand upright in an excessive level in case that a vehicle collides, there is a danger that an occupant of the vehicle can not preferably be protected by means of a seat belt and an air bag, or the like. JPH11-334437A describes a conventional occupant protection apparatus designed to overcome the problem described above. The conventional occupant protection apparatus includes a prediction sensor for predicting a collision of the vehicle with an object approaching from backward of the vehicle, a reclining sensor for detecting a reclining angle of a seat back, a control means for actuating a seat belt pretensioner when a collision is predicted by the prediction sensor, and a seat back-angle control means for changing the reclining angle of the seat back into a predetermined range when the reclining angle of the seat back is out of the predetermined range on the basis of a detection output of the reclining sensor.
As described above, when the seat back, or the like, is moved to an appropriate position for protecting an occupant when a collision of the vehicle is predicted, because there are cases that time is very short from when the collision of the vehicle is predicted to when the vehicle actually collides, the seat back or the like need to be moved at high speed. However, because a voltage of a power source utilized when the collision is predicted is the same one as utilized in a normal state, the seat back cannot be moved at a high speed. In addition, because of an action of the seat back or the like performed when a vehicle collision is predicted, a voltage of the power source can be made lower, and thus there can be a danger that a sufficient power can not be supplied to another part of the vehicle because of this voltage lowering of the power source.
A need thus exists for an occupant protection apparatus for a vehicle enabling an action of some part of a vehicle such as a seat or a window performed when a collision of the vehicle is predicted. It is preferable that a sufficient power can be supplied to another part of the vehicle even in the case described above. The present invention has been made in view of the above circumstances and provides such an occupant protection apparatus for a vehicle.